A few years back, a remarkable new hypothesis made its way into the scientific zeitgeist – namely, that life is an inevitable consequence of physics. The author of this concept, an associate professor of biophysics at MIT named Jeremy England, has now published the first major papers testing out this idea, and it’s looking like he might be right on the money.
England’s hypothesis is a key bridge between physics and biology. Although it’s not yet conclusively proven, it potentially holds the key to answering one of the greatest questions of all: Where did we come from?
Here’s what his work is arguing. Thanks to the second law of thermodynamics, the universe is heading towards a state of complete structural disorder. It’s tumbling towards a state where everything is essentially the same no matter how the constituent parts are arranged.
This is known as “maximum entropy”, where everything on an energy level is balanced, everywhere.
Right now, though, there are pockets of order, of low entropy – objects and things that cannot be atomically rearranged and still be the same thing (planets and life, for example). They are the exceptions to an increasingly disordered universe, something first highlighted by Schrodinger’s seminal 1944 essay What Is Life?
Think of a pool of water with three color dyes dropped in it. Initially, they remain as separate dots far apart, but over time, the colors spread out, mix, and in the end, there’s just one single color. That’s the universe; the dots, in this case, can be pockets of biological life.
A rather wonderful explanation of entropy. BBC via YouTube
England is suggesting that biology arises because, in certain environments – like on planets – where the energy balance is so out of whack, physics guarantees that atoms rearrange themselves to be able to deal with the chaotic flow of energy. These atomic structures just happen to resemble what we refer to as “life”.
As England famously said back in 2014: “You start with a random clump of atoms, and if you shine light on it for long enough, it should not be so surprising that you get a plant.”
Using cutting-edge computer simulations, England and his colleagues dumped basic chemical compounds into an early-Earth like environment and watched what happened.
The first paper, in the Proceedings of the National Academy of Sciences, shows that life-like structural arrangements of atoms spontaneously arise. Importantly, biological inputs and variables – the behavior of cells, the formation of DNA, and so on – weren’t preprogrammed into the simulations.
The second, published in Physics Review Letters, shows that when driven by an external energy source – the Sun, in this case – these atoms rearrange themselves in order to absorb and emit the energy more efficiently. Perhaps most remarkably, these life-like structures started to copy themselves in order to better handle this energy flow.
Just using the laws of physics, life appears and replicates without needing anything other than a few basic chemicals and the Sun. So – has the greatest question of all been answered? Perhaps, but this is still a nascent hypothesis, one of several.
England has also received as much praise for his inventiveness as he has attracted criticism for his lackadaisical definition of “life”. Admittedly, life is defined pretty poorly, but some are suggesting that the life-like arrangements seen in England’s work are too abstract to be properly referred to as being “alive”.
It’s a compelling hypothesis nevertheless, one that clearly shows order arising from a system trending inexorably towards total disorder. If it’s correct, then it would be the most significant addition to evolutionary theory since Darwin’s magnum opus was first released.
[H/T: Quanta Magazine via Wired]